Arrows are slightly stiff, not massively if you've got a 27"-29" drawlength.. Shouldn't be the cause of your left impacts or the sight being maxxed out to the left to compensate

This sounds more like staring at the sight pin issue, although it doesn't explain the taking the sight off, I'm guessing you're looking at the point when you shoot barebow

If you shoot with both eyes open then I'd guess that your head probably isn't turned enough because you're still new to archery, as you can't see over your nose the left eye is becoming dominate and causing your left impacts

You can either close your left eye and line everything up or learn to look at the target and place the ghost image of the sight pin on the target.... It will feel weird but you can kinda ignore the sight pin, look at the target and bring the pin across/down into position to shoot, you'll see through it and be able to place it on target correctly... You may see two ghost sight pins, use the one that's the furthest left... You have to kinda acknowledge its there but not look directly at the pin